An array antenna is a group of two or more single antennas arranged in a certain space. Array antennas include: multi-beam antenna, single-beam antenna without grating lobes, and single-beam antenna with grating lobes. The multi-beam antenna is an antenna that uses phase shift control to intentionally generate multiple expected beam orientations. When a grating lobe of the single-beam antenna with the grating lobes is an adjustable single beam generated on the array antenna, due to limitations of physical parameters, image beams are generated in other directions, and the grating lobe leaks energy in unexpected directions.
In the prior art, because all beams of the array antenna are transmitted or received by centering on the antenna, the beam transmitting angle of the array antenna is restricted by the structure of the array antenna, and the angle of the beam in the array antenna is not flexibly adjustable.